"Ultimately, we will all be judged by a simple question: Did we stop Iran from getting a nuclear weapons capability?" said Rep. Ileana Ros-Lehtinen, R-Fla., during the House debate. "If the answer is no  if we fail  then nothing else matters. If we fail, it would be of no comfort to the American people, whose security and future would be put in danger. If we fail, it would be of no comfort to our ally Israel, whose very existence would be put in danger."

Ros-Lehtinen, the chairwoman of the House Foreign Affairs Committee, and Sen. Tim Johnson, D-S.D., chairman of the Senate Banking Committee, negotiated the compromise bill.

Johnson called attention to the "sputtering" negotiations between the West and Iran over its uranium enrichment.

"Economic sanctions are not an end: They are a means to an end," Johnson said. "That end is to apply enough pressure to secure agreement from Iran's leaders to fully, completely and verifiably abandon their illicit nuclear activities."

The legislation would impose sanctions on anyone who mines uranium with Iran; sells, leases or provides oil tankers to Tehran; or provides insurance to the National Iranian Tanker Co., the state-run shipping line. The bill seeks to undermine Iran's ability to repatriate revenue from the sale of crude oil.

The bill would penalize anyone who works in Iran's petroleum, petrochemical or natural gas sector, or helps Tehran's oil and gas industry by providing goods, services, technology or infrastructure.

"Our current sanctions, and a recent European Union ban on purchasing Iranian oil, have already had an impact," said Senate Majority Leader Harry Reid, D-Nev. "In spite of the rhetoric coming out of Iran, the regime is clearly feeling the heat. Oil exports are down by 50 percent, and the Iranian currency has lost nearly 40 percent of its value."

Separately this week, President Obama announced new penalties on Tehran's energy sector and on foreign banks in China and Iraq that the U.S. says help the Islamic republic evade international penalties.

The United States and Europe insist that the penalties are working. Iran has exported 2.5 million barrels of oil a day to Europe, China, India, Japan and South Korea. U.S. officials say the penalties have reduced Iran oil exports to less than 1.8 million barrels a day, costing Tehran about $63 million daily.

But in Jerusalem on Wednesday, Israeli Prime Minister Benjamin Netanyahu challenged the effectiveness of sanctions.

The compromise bill would target the Iranian Revolutionary Guard Corps and anyone who assists the paramilitary group, including foreign government agencies.

The bill also would deny visas and freeze assets on individuals and companies that supply Iran with technology that could be used against its citizens, such as tear gas, rubber bullets and surveillance equipment. The bill extends those sanctions on human rights violators to Syria, where President Bashar Assad's regime is accused of a bloody crackdown against protesters.

The bill requires companies that trade on the U.S. stock exchange to disclose any Iran-related business to the Securities and Exchange Commission.

Late last year, Congress overwhelmingly approved sanctions targeting foreign financial institutions that do business with Iran's central bank by barring them from opening or maintaining correspondent operations in the United States. Those sanctions applied to foreign central banks only for transactions that involve the sale or purchase of petroleum or petroleum products.

The new bill expands on those penalties.

"These provisions are very important, but the Iranians should not be fooled into thinking that this is the last word on sanctions. Far from it," said Rep. Howard Berman of California, the top Democrat on the Foreign Affairs Committee.

A handful of lawmakers objected to the legislation, casting it as a step toward war.

Rep. Ron Paul, R-Texas, said the legislation should be called the "Obsession With Iran Act" and warned against "beating the war drums once again."

"We need to stop the wars. We don't have the money to fight these wars any longer," Paul said.

Rep. Dennis Kucinich, D-Ohio, said the bill sets the stage for another conflict

Berman dismissed that idea.

"This is not the next step to war. This is the alternative to war," he said.